What are the different types of hernias?

Hernias of various types can develop in men and women.

Inguinal or groin hernia: The most common type, inguinal hernias occur in about 2% of men in the United States. These hernias are divided into two different types, direct and indirect. Both occur in the area where the skin crease at the top of the thigh joins the torso (the inguinal crease), but they have slightly different origins. Both types of hernias are treated the same way.

Indirect inguinal hernia: An indirect hernia follows the pathway that the
testicles made during prebirth development and descends from the abdomen into the scrotum. This pathway normally closes before birth but remains a possible place for a hernia. Sometimes the hernial sac may protrude into the scrotum. An indirect inguinal hernia may occur in people of any age but becomes more common as people age.

Direct inguinal hernia: The direct inguinal hernia occurs slightly to the inside of the site of the indirect hernia, in a place where the abdominal wall is naturally slightly thinner. It rarely protrudes into the scrotum. Unlike the indirect hernia, which can occur in people of any age, the direct hernia almost always occurs in middle-aged and elderly people because the abdominal walls weaken with age.

Other types of abdominal hernias include the following:

Femoral hernia: The femoral canal is where the femoral artery, vein, and nerve leave the abdominal cavity to enter the thigh. Although normally a tight space, sometimes it becomes large enough to allow abdominal contents (usually intestine) to be pushed into the canal. A femoral hernia causes a bulge below the inguinal crease in roughly the middle of the thigh. Rare and usually occurring in women, femoral hernias are particularly at risk of becoming irreducible (can't push it back in) and strangulated (tissue becomes trapped and may die, a medical emergency).

Umbilical hernia: These common hernias (accounting for 10%-30% of all hernias) are often seen in babies at birth as a lump at the bellybutton (the umbilicus). This is caused when an opening in the abdominal wall, which normally closes before birth, doesn't close completely. If small (less than half an inch), this type of hernia usually closes gradually by itself by 2 years of age. Larger hernias and those that do not close by themselves usually require surgery when the child is 2-4 years of age. Even if the area is closed at birth, umbilical hernias can appear later in life because this spot remains a weaker place in the abdominal wall than other areas. Umbilical hernias can also appear in elderly people and middle-aged women who have had children, particularly obese people.

Incisional hernia: Abdominal surgery causes a flaw in the abdominal wall that must heal on its own. This flaw can create an area of weakness where a hernia may develop. This occurs after
a portion of all abdominal surgeries, although some people are more at risk. After open surgical repair, incisional hernias have a high rate of returning months or years after the procedure. However, in expert hands, minimally invasive surgical repair has a low recurrence rate.

Spigelian hernia: This rare hernia occurs along the lateral (outer) edge of the rectus abdominus muscle, which is several inches to the side of the middle of the abdomen.

Obturator hernia: This extremely rare abdominal hernia happens mostly in women. This hernia protrudes from the pelvic cavity through an opening in the pelvic bone (obturator foramen). No bulge appears, but the hernia can act like a bowel obstruction and cause nausea and vomiting. As there is no bulge and the pain can often be diffuse, this is a difficult hernia for the health-care provider to diagnose.

Epigastric hernia: Occurring between the navel and the lower part of the rib cage in the midline of the abdomen, epigastric hernias are usually composed of fatty tissue and rarely contain intestine. Formed in an area of relative weakness of the abdominal wall, these hernias are often painless and unable to be pushed back into the abdomen when first discovered. This type of hernia occurs mainly in men and in people 20-50 years of age.